Religion has also long been used as a tool to mobilize people for war. For most of human history, this was extremely functional. Societies organized around religions that could call for war—a jihad, a crusade—had a cultural-evolutionary advantage. Soldiers inspired by religion were more likely to defeat their enemies than those who were not. It is no accident that German soldiers in World War II were issued belt buckles inscribed with the words “God is on our side.”
